(19)

(11)

EP 2 396 508 A1

(12)

(43) Date of publication: 21.12.2011 Bulletin 2011/51 (21) Application number: 10703300.3 (22) Date of filing: 12.02.2010

(51) International Patent Classification (IPC):  E21B 43/36(2006.01) E21B 43/01(2006.01) E21C 45/00(2006.01) E02F 3/00(2006.01) (86) International application number: PCT/EP2010/051782 (87) International publication number: WO 2010/092145 (19.08.2010 Gazette 2010/33)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR (30) Priority: 13.02.2009 EP 09152818 (71) Applicant: Shell Internationale Research Maatschappij B.V. 2596 HR The Hague (NL)	(72) Inventors: EFTHYMIOU, Michalakis NL-2288 GD Rijswijk (NL) KLOMP, Ulfert, Cornelis NL-1031 HW Amsterdam (NL) PASFIELD, Thomas, Alexander NL-2288 GD Rijswijk (NL) SORENSEN, Kjeld, Aaby NL-2288 GD Rijswijk (NL) (74) Representative: Matthezing, Robert Maarten  Shell Internationale Reseach Maatschappij B.V. Intellectual Property Services P.O. Box 384 2501 CJ The Hague 2501 CJ The Hague (NL)